Gas turbine engines include a compressor section for compressing air, a combustor section for mixing the compressed air with fuel and combusting the mixture to generate exhaust, and a turbine section for converting the exhaust into torque. Portions of the compressor section, the combustor section, and the turbine section may include parts that move relative to adjacent parts. In that regard, it is desirable to provide lubrication to many of these locations. Double-walled tubes may be utilized throughout gas turbine engines to transport a lubricating fluid, such as oil. The inner tube may transport the fluid, and a passageway between the inner tube and the outer tube may collect and transport fluid that leaks from the inner tube to reduce the likelihood of the lubrication flowing freely within the gas turbine engine.